Each vehicle driving on a roadway must interact with other nearby vehicles. In high-speed, dynamic driving environments, a vehicle may sometimes change lanes without its driver being aware of the location of all the vehicles driving in close proximity to the lane-changing vehicle. This can create potential hazards for vehicles driving close to the lane-changing vehicle, and especially for vehicles driving relatively closely behind the lane-changing vehicle, in an adjacent lane. Thus, it would be beneficial to have a system that detects when vehicles are changing lanes, and which can alert drivers of other, non-lane changing vehicles to the lane change.
Also, there are driving conditions where the actual lanes being used by traffic are different from marked lanes. Such conditions may occur, for example, due to road construction, temporary lane closure, or accident investigation. These actual lanes being traveled by vehicles are still constrained by road geometry, but may differ from lanes marked by conventional lane markers. Furthermore, in some cases, conventional lane markers and road edges may be difficult to detect visually or using camera systems. Thus, it would be beneficial to have a system capable of determining the road geometry and lane paths based on the actual travel paths of vehicles and independent of normal lane boundary markers.